Pages

Tuesday, December 4, 2012

Energy levels in the ground

2 Dec 2012: The ground temperature is doing quite well considering how grim the summer was - it is still 11ºC…. I usually test on a Sunday night at midnight, and we have been lucky with some sunny Sundays, even if mid week was raining. The ground temperature graph from August 2009 to the start of December 2012 shows how consistent the temperature has been since the Sunbox was installed, despite the variations in climate. Ground deep down below is not really affected by annual temporary climatic variations, the difference to the temperature is made by the amount of energy that the house demands of the heat pump, i.e. the house demand is governed by the weather, and if it is cold, the house demands more!

Ground Temperatures Aug'09-Nov'12
Energy levels over three years in a sequential line. In both the above graphs, the downward 'blip' which occurred when the Sunbox was out of action for a month in Mar-April 2012 is very visible.

Energy Levels in the 3 years, overlaid for comparison.

These are derived from my ArchiCAD thermal model written during summer 2012.
Each year is colour coded. These do show the variations in weather during the three years. As I look at the colours, I can recall the weather.

The Red line is 2009, prior to the Sunbox installation - the curve follows a familiar shape, but consistently lower than in the later years. The autumn was a fairly gentle slide into winter.

The Black line is 2010, the year of 'two winters' - which started with a very cold January and spring (snow and freezing temperatures) and in the same year we had the coldest December on record - so there is a steep fall in the last month. We had a reasonably sunny summer, so the energy level was lifted as soon as the Sunbox was operating in March April 2010.

The Blue line was 2011 which was thermally mild all through the cold seasons and with a fine summer. It did not begin to get cold until mid December.

The Yellow line is 2012, the current year and this started with a high energy level thanks to 2011's weather. Weeks and months of grey conditions and rain resulted in a faster withdrawal of energy and a reduced solar capture, so the energy level reverted to that of 2010, with minor variations - we had an earlier summer peak, and a flatter decline because the recent autumn weather has been rainy but not cold. For a month of the spring, the Sunbox was not working due to a leak, and I had to go to New York for a time, and leave it not working (system now has an additional expansion tank added!)

March 2015: Work on the solar dehydrator has been progressing well, and it is nearly complete, lacking merely the top surface of the sola...

Peveril Solar House

Welcome to Charging the Earth!

PEVERIL SOLAR is the first house in the UK to be entirely solar heated all year round! It is Carbon Net-Zero. It is an 'Active House' balancing inputs and outputs. PV generation and heating system consumption are in favourable balance using concepts of energy storage. Others claiming houses to be the first date from 2013 (and are unbuilt); this house exists and was carbon zero since 2011.

The name 'Charging' refers to 'storing energy underground': we have custom-built solar collectors, Surya Sunboxes, with ETFE front surfaces, to pump solar heat deep down into the earth. The building's heat pump gets all of this back in Realtime (immediately), Diurnially (later during the evenings) or Interseasonally (in Winter, months after the Summer).

Thus, we are augmenting the heatpump by storing long term heat in the summer, and we are defrosting the ground in winter-spring conditions, supplying solar energy directly to the heat pump, through its ground loop.

The five-way pentangle of Grid, Borehole, Heat pump, PV roof and Sunboxes have made the house Carbon Zero (for metered consumption). It's working, and we will continue to record data, to maintain that efficiency, and write it up in this website through to next year and beyond.

During theAutumn of 2012, we built a small house extension that is ultra insulated, with a higher energy gain than it loses.

Note, that we still have a net import of power from the Grid, because we still need power for lighting, cooking and appliances. But for the building emissions (as opposed to lifestyle emissions), we have achieved a credit balance of the regulated quantities, as recorded by meters.

The web-log follows the project from this general idea in Aug. 2009 to a technology of Surya Sunboxes, which seem to be effective - reducing energy costs of the house. Some of the Tabs will help you to get background and theory. You can click below to 'Follow Blog' to get email notifications - or email me. Please add Comments to the blog entries. If you find items in the Glossary that need explaining better, please ask. Thankyou!

Publications

Equipment sponsor

Kingspan, for Varisol Tubes

Equipment Sponsor

MG Renewables

Equipment sponsor

Ice Energy Heat Pumps

Equipment Sponsor

Holscot, for ETFE panels, re-fronting the Sunbox

About the Author...

David Nicholson-Cole is a Lecturer in Architecture at the University of Nottingham, with 35 years experience of architectural teaching and practice, which has included special interests in construction, building information modelling, tall building design and renewable energy technologies.

Finally, thanks to my deceased aunt, Margaret Cringle (1915-2008) whose legacy paid for most of the cost of this project - as one who was always turning lights out to save electricity, she would be very pleased!